Childhood trauma exposure is strongly associated with psychopathology onset in children, adolescents, and adults, accounting for a substantial proportion of mental disorders in the population. However, the neurodevelopmental mechanisms that explain the association between child trauma (CT) and psychopathology remain poorly characterized. In particular, research examining how CT influences brain development remains in its infancy. Yet understanding the neurodevelopmental processes that are disrupted as a result of CT exposure will provide critical information about the pathways linking adverse environments to psychopathology. To that end, the proposed project examines the impact of CT on the development of neural networks involved in emotion regulation, a plausible neurobiological pathway linking CT to psychopathology. The proposed research addresses Objective 1 of the NIMH Strategic Plan by examining how specific types of early environmental experience-child physical or sexual abuse and domestic violence-alter neural structure and function in ways that might increase risk for psychopathology. We hypothesize that CT exposure disrupts the development of the prefrontal cortex (PFC) and amygdala, resulting in atypical patterns of neural function and reduced structural and functional connectivity between these regions. We aim to build knowledge of how environmental experience shapes development in Negative Valence Systems by applying a neurobiological model distinguishing between emotional reactivity and both implicit and explicit emotion regulation to investigate this hypothesis. Specifically, we propose that a) CT exposure leads to heightened amygdala reactivity and that reactivity is positively associated with trauma severity and chronicity, and b) chronicity of exposure to CT is additionally associated with deficits in emotion regulation, involving poor PFC modulation of amygdala reactivity resulting from low structural and functional connectivity between these regions. The conceptual model will be tested by acquiring structural and functional MRI data in a sample of 8- 16 year olds; half with exposure to child maltreatment or domestic violence and half without exposure to CT or interpersonal violence. The sample will be recruited to ensure variation in CT chronicity and severity and to allow us to examine associations of CT with neural structure and function in children with and without pre- existing internalizing psychopathology. The proposed study builds on existing research examining the influence of early deprivation on brain development by examining how experiences of threat influence neural structure and function in children. Study findings will provide critical information regarding the specific aspects of emotional reactivity ad regulation that are disrupted following CT exposure. Elucidating these mechanisms will not only build knowledge of how adverse environments alter neural development in ways that might increase risk for psychopathology, but will also suggest possible targets for preventive interventions aimed at reducing psychopathology risk in children exposed to trauma.